Image Caption: Meteor Crater, Arizona and Roter Kamm Impact Crater, Namibia. Prior to 1925 Meteor Crater was the only recognizable impact crater. Located 60 km ESE of Flagstaff, Meteor Crater is classified as a simple crater (bowl-shaped depression with no central peak or ring structure) with a diameter of 1.2 km. The age of Meteor crater has been estimated to be about 50,000 years. The square shaped appearance is due to local jointing in the surrounding rock.

Roter Kamm is a circular crater located in the Namib Desert of southwest Africa. The age of the impact crater is unknown, but is believed to be relatively young. Roter Kamm is similar in appearance to Meteor Crater, but it's diameter is somewhat larger at 2.5 km.